Centrifuge nozzle construction



30, 1954 D. MILLARD CENTRIFUGE NOZZLE CONSTRUCTION 3 Sheeis-Sheet 1 Filed Jan. 22, 1952 & m m m lore/7 0 MY/ srd BY JZZJ A v ATTORNEY) Nov. 30, 1954 L. D. MILLARD 2,695,748

CENTRIFUGE NOZZLE CONSTRUCTION Filed Jan. 22, 1952 3 Sheets-Sheet 2 IN V EN TOR. Zora 5. 47/7/{51/"0 United States Patent CENTRIFUGE NOZZLE CONSTRUCTION Loren D. Millard, San Mateo, Calif., assignor to Merco Centrifugal Co., San Francisco, Calif., a corporation of California Application January 22, 1952, Serial No. 267,648

9 Claims. (Cl. 233-47) This invention relates generally to the construction of centrifuge rotors, and more particularly to nozzles for the discharge of centrifugally separated fractions.

Centrifuge rotors are usually fitted with one or more sets of nozzlesfor the discharge of centrifugally separated fractions. In order to facilitate replacement of wornnozzles, or the clearing of plug discharge orifices, it has been common to detachably mount the nozzles in an annular wall of the rotor. The methods of attachment which have been used require access to the interior of the rotor inorder torernove or apply certain component parts of the nozzle assembly (see for example Peltzer 2,060,239). This is alabor and time consuming operation which requires complete shut-down of the machine, andwhich may seriously interfere with processing requirements of the system in' which the machine is used.

It is an object of the present invention to provide a centrifuge rotor and nozzle. construction which makes possiblevthe removal and replacement of nozzles from the exterior of: the "rotor and'without access to the rotor interior.

Another object of the invention'is to provide a rotor and nozzle construction of the above character' which greatly facilitates the labor and time required for the removal or replacementof anozzle.

Another object of the invention is to provide novel interlockingmeans for retaining discharge nozzles of a centrifuge rotor in operative position.

Another object of the invention is to provide a novel nozzle constructionwhichfacilitates maintenance of a seal between the nozzle assembly and the centrifuge rotor.

Another. object of theinvention is to provide a nozzle constructionwhichfacilitates making adjustments to provide a desired direction of discharge.

Afurther object of the invention is to provide a relatively simple nozzle construction which can be readily manufactured, and-which facilitates the use of relatively hard wear-resisting material.

Additional objects and. features of the invention will appearifrom the following description in-which the preferred-embodiments have been set forth in detail in conjunction with the accompanying drawing.

Referring to the drawing:

Figure 1 is a detail in section illustrating a wall portion'of a centrifuge rotor equippedwith my nozzle construction.

Figure 2 is adetail looking toward the right hand side of Figure. 1.

Figure 3 is a detail in section like Figure 1, but showing another embodiment of the invention.

Figure 4 is a detail looking toward the. right hand side ofFigure 3.

Figure 5 is a detail in section like Figure 1 but illustrating another embodimentof the invention.

Figure 6 is a detail taken looking towards the right handsideofFigure 5.

Figure. 7 is a detail in section like Figure 1 but illustrating another embodiment of the invention.

Figure 8 is a detail looking toward the right hand side of Figure 7..

Figure 9 is a detail in section like Figurel but showing another embodiment of the invention in which the orifice discharges in a non-radial direction aligned with the. axistof the nozzle assembly.

Figure. 10 is a cross-sectional detail taken along the line 16*) of Figure 9.

Referringfirst to the embodiment illustrated. in Figice ures 1 and 2, I have shown an annular wall 10 which forms a part of a centrifuge'rotor, and which for example may be a portion of the peripheral wall surround ing the separating chamber. The curved surface. 12 is the confining surface of the separating chamber, and the surface 13 is an exterior periphery.

My improved nozzle construction is designated generally at 14, and in practice a plurality of such nozzle assemblies are mounted at regularly spaced intervals about the periphery of the rotor.

In the construction of Figure 1, the nozzle assembly includes the body 16, which is machined to provide the cylindrical surface 17. The wall 10is provided with a cylindrical bore 18 which is dimensioned to snugly accommodate the body, andthe axisof this bore is radial with respect to the axis of the rotor. Leakage between the body 16 and the wall It is prevented by suitable means such as the resilient. seal ring 19; The particular seal illustrated is of the 0 ring type, and is loosely accommodated within an annular groove 20 formed in the periphery of the body 16. The resilient O ring is dimensioned whereby it is compressed a slight amount-in a radial direction, to maintain sealing contact between the body and the surface of the bore 18. Sealing means of this character is capable of withstanding relatively high fluid pressures, while at the same time permitting ready removal.

The outer end portion of the body 16 is provided with a bore 21, which is fitted with insert 22 which can be of metal or some erosion or corrosion resistantmaterial, such as hard metal, metal alloy like tungstencarbide, ceramic or jewel. It can be held in place by suitable means such as hard solder, brazing or cementing. The body is also bored to provide the fluid passage 24, whereby a centrifugally' separated fluid fraction may pass through bore 24and discharge through orifice 23. Preferably the inner end face 26 of the insert 22 is inclined to both the axis of the insert; and the axisof the bore 24, as illustrated. According. to my observations, this serves to minimize wear; of the nozzle, which I attribute to the fact that it tends to prevent or reduce swirlof material within the body 16, andparticularly as material flows into the orifice 23.

Preferably the outer end face of the body 16 is flush with the outer peripheral surface 13. To enable free discharge of material the wall 10 is provided with a cavity 27 which is dimensionedin order to enable free discharge of material from the orifice 23. It will be noted that the discharge is directed backwardly with respect to the direction of rotation of the rotor.

Means is provided for detachably securingthe body. 16 within the wall' 10. In this instance the means consists of a lug 28 which is formed integral with the body and which is preferably on that side of 'the body diametrically opposite from the insert 22. The wall 10 is machinedto provide the arcuate groove or recess'29, which is dimensioned to accommodate the lug 28. The groove 29 is not completely circular, and its ends open into the cavity 27. When the body, is positioned as shown. in Figure 2, the lug 28is disposed equidistant from the ends of the groove 29, and serves to securely lock the body within the wall 10. However, when the body is turned from the position shownin Figure 2, the lug'28 is brought into registration with the cavity 27, and the body is then free to be retractedfrom the rotor wall. Suitable means can be provided to facilitate turning the. body. Thus in Figures-1 and 2 the outer end of the body is provided with a slot 31 which can be engaged by a suitable turning tool.

The nozzle securing means described above. firmly locks the nozzle within the rotor wall 10 for normal operation of the machine. The resilient O ring 19 forms a fluid tight seal between the body 16 and the rotor wall, and is capable of withstanding the relatively high fluid pressures to which the nozzle is subjected. When-it is desired to remove a nozzle, the nozzle body 16 is turned 180 from the position shown in Figures 1 and 2, which frees the lug 28 with respect tothe groove 29, thus permitting the complete nozzle to be withdrawn. When it is desiredto insert a nozzle the lug 28 is aligned with the cavity 27, after which the body 16 is inserted within the bore 18 .to a position non-radial direction.

- the angle of discharge can be adjusted as desired by turning the nozzle body clockwise or counterclockwise, from the position illustrated in Figure 2. This serves to cause the orifice 23 to discharge material in a direction either above or below a plane normal to the axis of the rotor and contiguous with the axis of the nozzle. The resilient ring provides sufiicient friction to hold the nozzle in an adjusted position.

Figures 3 and 4 illustrate another embodiment of the invention, which is similar in some respect to Figures 1 and 2, but which utilizes an additional part for locking the nozzle to the rotor wall. Thus in this instance the rotor wall 32 is provided with a bore 33 for receiving the body 34. The body 34 is provided with the resilient 0 ring 36, to establish a seal, and also it is provided with the insert 37. The orifice 38 in the insert discharges through the cavity 39. The body is provided with an integral lug 41, which is accommodated within the arcuate groove 42. Except for dimensions, the parts just described are similar to Figures 1 and 2.

The additional locking element used in Figures 3 and ,4 consists of a screw or threaded plug 43. This screw is threaded into a bore 44 provided in the wall 32, and a part of this bore extends through the lug 41. With the screw 43 in place, as illustrated in Figure 3 and 4, it serves as an interlock between the lug 41 and the rotor wall, and therefore prevents rotation of the body 34. When it is desired to remove the nozzle, screw 43 is first removed, after which the body 34 can be rotated 180 and retracted.

In the embodiment of Figures and 6, the body and its associated parts are proportioned the same as in Figures 3 and 4. The locking screw 43 is omitted whereby the lug 41 becomes the sole means for locking the nozzle within the recess 42. The rotor wall 32 is provided with a threaded bore 46, which is engaged by the screw 47. The inner end of this screw engages the adjacent side face 48 of the lug 41, whereby the screw forms a stop which limits rotation of the body 34 in a counterclockwise direction as viewed in Figure 6.

With the embodiment of Figures 5 and 6, the screw 47 is set in accordance with the angle of discharge desired. When a nozzle is removed it is turned in a clockwise direction as viewed in Figure 6, to bring its lug 41 into registry with the cavity 39. When the nozzle is again inserted in the rotor, it is turned counterclockwise until the end face 48 of the lug engages the screw 47. This serves to establish the desired discharge angle. Preferably the orifice 38 is displaced to one side of the axis of body 34 (Figure 6) whereby the reaction of the jet tends to rotate the body to hold the lug 41 against the screw 47.

In the embodiment illustrated in Figures 7 and 8, the rotor wall 51 is likewise provided with a radial bore 52 to accommodate the body 53. The body is provided with an inner cylindrical bore 54, which is fitted with the insert 56 of wear resisting material. A resilient O ring 57 forms a fluid tight seal between the body and the rotor wall, and

another resilient 0 ring 58 forms a seal between the body and the insert 56. The outer end portion of the insert is provided with a discharge orifice 59, which discharges through the opening 61 and the rotor cavity 62. Suitable cushioning means 63, such as a layer of synthetic resilient rubber, is preferably inserted between the outer end of the insert and the adjacent portion of the body 53.

The body 53 is provided with the integral lug 64, which is accommodated within the arcuate groove 66. Here again the interlock is such that when the nozzle body is turned 180 from the position illustrated in Figures 7 and 8, the lug 64 is brought in registry with the cavity 62, and then the nozzle is free to be retracted.

A feature of the construction illustrated in Figures 7 and 8 is that the insert 56 is readily removable for replacement.

In the construction illustrated in Figures 9 and 10, the bore which serves to receive the nozzle is disposed in a ring 74. The body is also fitted with the insert 76 of wear Thus the rotor wall 71 is provided 0 resisting material which has a discharge orifice 77 aligned with the axis of the bore 72. The orifice 77 discharges through the larger opening 78, and through the rotor wall cavity 72. The outer end of the body 73 is provided with the integral lug 81, which is adapted to engage within the arcuate groove 82. By turning the body from the position shown in Figures 9 and 10, the lug 81 is removed from the groove 82, thereby permitting the nozzle assembly to be retracted from the rotor.

It will be evident from the foregoing that I have provided a nozzle construction which enables removal and replacement of nozzles without access to the interior of the rotor, or in other words by operations which are completely exterior. Therefore nozzles can be replaced, or serviced to unplug the same, with a minimum expenditure of time and labor. My nozzle construction can be used to advantage with a wide variety of centrifuges, including particularly centrifuges of the continuous operating type as shown for example in Patent 1,945,786. The underfiow discharge nozzles of such centrifuges frequently handle components which may tend to cause relatively rapid Wear, or plugging or clogging of the discharge orifices. With a machine equipped with my nozzle construction, nozzles can be quickly replaced as desired, whereby the machine may operate continuously over long periods with a minimum of shut-down time for replacement or servicing.

I claim:

1. In combination with a centrifuge rotor having an annular wall provided with an opening to receive a discharge nozzle, of a discharge nozzle comprising a body dimensioned to slidably fit within said opening when applied from the exterior of the rotor, said body being formed to provide a discharge orifice, means carried by the outer end portion of said body forming a detachable interlock between the body and said wall, said last named means including an element secured to the body adapted to interlock with the wall responsive to turning of the body, and means disposed on the inner side of said interlocking means for forming a seal between the body and said wall.

2. in combination with a centrifuge rotor having an annular wall provided with an opening to receive a discharge nozzle, of a discharge nozzle comprising a body annularly contoured to slidably fit within said opening when applied from the exterior of the rotor, said body providing a material discharge orifice, a lug carried by the body, means forming an interlocking recess in the wall for receiving said lug responsive to turning of the body after application of the nozzle within the wall, and means disposed on the inner side of the recess for forming a seal between the body and said wall.

3. In combination with a centrifuge rotor having an annular wall provided with an opening to receive a discharge nozzle, of a discharge nozzle comprising an annular body dimensioned to slidably fit within said opening when applied from the exterior of the rotor, means including a resilient seal ring carried by the body and serving to establish a fluid tight seal between the body and the wall, and means forming a detachable interlock between the outer end portion of the body and said wall, the seal ring being disposed inwardly of said last named means.

4. A nozzle construction as in claim 1 in which the orifice discharges in a direction which is generally lateral to the axis of the body, and in which the body can be adjusted relative to the wall to adjust the angle of discharge.

5. A nozzle construction as in claim 4 in which an adjustable member is provided for adjusting the normal positiltlan of the nozzle body with respect to the direction of disc arge.

6. A nozzle construction as in claim 1 in which the orifice discharges in a direction in alignment with the axis of the body, and in which the axis of the body is inclined rearwardly with respect to the direction of rotation of the rotor.

7. A nozzle construction as in claim 1 in which the body is provided with a removable liner, the liner being formed of hard wear-resisting material and being provided with an opening to provide said discharge orifice.

8. In combination with a centrifuge rotor having an annular wall provided with a smooth cylindrical bore to receive a discharge nozzle, of a discharge nozzle comprising a body having a smooth surfaced cylindrical portion dimensioned to slidably fit within said opening when applied from the exterior of the rotor, means including a resilient seal ring carrid-bysaid cylindrical body portion and serving to establisha fluid tight seal betwen the body and the adjacent surface of 'said bore, and means forming a detachable interlock between the outer end portion of,

the body and said wall, said means including a lug carried by the outer end portion of the body and an interlocking recess in the wall for receiving said lug.

9. In combination with a centrifuge rotor having an annular wall providedwith a radially disposed smooth cylindrical bore to receive a discharge nozzle, of a discharge nozzle comprising a body having a smooth surfaced cylindrical portion dimensioned to slidably fit within said opening when applied from the exterior of the rotor, means including a resilient seal ring carried by the cylindrical body portion and serving to establish a fluid tight seal between the body and the cylindrical surface of said bore, said cylindrical body portion having an axially disposed passage and the outer end portion of the body hav ing a discharge orifice communicating with the passage and directed to discharge material laterally with respect to the axis of said cylindrical portion, said wall having a cavity adjacentone side of said bore for accommodating material discharging from said orifice, the outer end of the body being'substantially flush with the outer periphery of the wall, '*a rid means forming a detachable interlock between'the outer end portion of the body and said wall, said means including a lug attached to the outer end portion of the body and located diametrically opposite said orifice and a lug accommodating recess formed in said wall located diametrically opposite to said cavity.

References Cited in the tile of this patent UNITED STATES PATENTS Number Name Date 2,060,239 Peltzer Nov. 10, 1936 2,410,313 Strezynski Oct. 29, 1946 2,590,735 Svensjo Mar. 25, 1952 

